7409 50 | = | 1 | ÷ | 2 | × | ( | ( | 28589 100 | − | 21009 100 | ) | x | ÷ | 2 | + | 21009 100 | × | 2 | ) | x |
| 方程右边 = | 1 2 | ( | ( | 28589 100 | − | 21009 100 | ) | x | ÷ | 2 | + | 21009 100 | × | 2 | ) | x |
7409 50 | = | 1 2 | ( | ( | 28589 100 | − | 21009 100 | ) | x | ÷ | 2 | + | 21009 100 | × | 2 | ) | x |
| 方程右边 = | 1 2 | ( | 28589 100 | − | 21009 100 | ) | x | ÷ | 2 | × | x | + | 1 2 | × | 21009 100 | × | 2 | x |
| = | 1 4 | ( | 28589 100 | − | 21009 100 | ) | x | x | + | 21009 100 | x |
| = | 1 4 | × | 28589 100 | x | x | − | 1 4 | × | 21009 100 | x | x | + | 21009 100 | x |
| = | 28589 400 | x | x | − | 21009 400 | x | x | + | 21009 100 | x |
7409 50 | = | 28589 400 | x | x | − | 21009 400 | x | x | + | 21009 100 | x |